COLUMBIA, Md.--(BUSINESS WIRE)--Osiris Therapeutics, Inc. (NASDAQ: OSIR), announced today interim one-year results from its groundbreaking clinical trial evaluating Prochymal® (remestemcel-L) for the treatment of patients experiencing first-time acute myocardial infarction. The trial is the largest study of allogeneic or "off-the-shelf" stem cells ever conducted in heart attack patients. A total of 220 patients were given a single infusion of either Prochymal or placebo through a standard intravenous line within seven days of an acute heart attack.